How to change the extruder board (BCN3D Sigma)



Allen key 2 mm
Allen key 2.5 mm


1. Please, check the extruder board version on your printer:

new-extruder-board-bcn3d old-extruder-board-bcn3d

R16 Older Extruder board

R17 | R19 Extruder board


If you have the R16 extruder board version, you’ll need to replace both the extruder board and the cooler fan. Please follow the steps explained in this article:

Article: How to change/swap the cooler fan


2. Remove the two Allen screws from the connection cover. Remove and slide the cover-up. You can hold the cover as the following picture. screw-icon x2 M3 12mm

New Project (1) (1)



3. Disconnect the cables of the hotend, the endstop and the two fans. Also carefully open the clip of the flat cable and disconnect it.

Annotation 2020-07-22 111639 Annotation 2020-07-22 111639 (1)

_MG_2665 (3)


4. Remove the extruder board unscrewing the Allen screws. screw-icon x2 M3 6mm

New Project (1) (2) (1)

New Project (1) (2) (2)


5. Unfasten the two screws holding the extruder board, making sure to keep the nylon washers.

screw-icon x2 M3 6mm

washer-icon x4




6. To reassemble the new extruder board, follow these instructions in reverse order. Don't forget to install the nylon washers before reinstalling the extruder board.



To reassemble the component, follow the above steps in reverse order.

Forum community 

Repair didn’t go as planned? Check out our forum community for troubleshooting help.


It's important to keep your printer in good shape to make the most out of it. In this chart you can find a list of the extruder maintenance procedures and how frequently these should be done. Maintenance Plan


bcn3d-recycle  Take your e-waste to a certified recycler. Check how we do it in BCN3D.



Parts   Buy these parts
old-extruder-board-bcn3d Sigma / Sigmax - R17 | R19 Extruder Board SKU 16100 



check flat cable eng


check mainboard fuse eng


You can help improve the BCN3D Knowledge Base.

If you feel there are guides that we are missing or you found any error, please use this form to report it. Report form :)